Put some salt or other small objects on the imager chip’s glass cover, assemble the microscope with the LED end cap on top, turn on the LED, and behold the microscopic world. Since we didn’t touch the web camera’s electronics, all of its software will work.

You can put solids (sand, salt, sugar), liquids (plankton samples, murky outdoor water), and objects (moth, fly) directly on the imager’s glass cover. As with a regular optical microscope, the image comes from light shining through the subject.

The magnification of the lensless microscope is the ratio of the monitor width to the imager sensor width (about 7mm).

Use a dry cotton swab to clean liquids off the glass.

Use a straw to blow solids off (close your eyes!), or clean the glass with an alcohol-soaked swab.

Note that you’ll get false colors due to imperfections in the imager’s color filters and camera software. Try different-colored LEDs for interesting effects. If you’re ambitious, you can hack a megapixel camera in the same way and obtain higher resolutions — potentially much higher, depending on the camera.

See a video of rotifer plankton taken by the lensless microscope at http://www.makezine.com/go/plankton.

Moth, VGA webcam imager, red LED.

Salt crystals, VGA webcam imager, white LED.

Copepod plankton, VGA webcam imager, blue LED.